i have just removed plaster from a wall in my house to insulate it properly from the inside. So far i have built a stud wall from 4x2cls timber and have been given some 50mm celotex sheets from a friend. Now on this wall is 2 double sockets of which i have just removed the plaster from the cables an boxes now im putting the sockets back in the new wall. How do i run the cable down the studs? Does it have to be a certain depth back from the front of the stud? my current space between front of stud and insulation is around 40mm any help would be great?